The value of flow cytometric analysis of platelet glycoprotein expression of CD34+ cells measured under conditions that prevent P- selectin-mediated binding of platelets

In the present study, we show by adhesion assays and ultrastructural studies that platelets can bind to CD34+ cells from human blood and bone marrow and that this interaction interferes with the accurate detection of endogenously expressed platelet glycoproteins (GPs). The interaction between these cells was found to be reversible, dependent on divalent cations, and mediated by P-selectin. Enzymatic characterization showed the involvement of sialic acid residues, protein(s). The demonstration of mRNA for the P-selectin glycoprotein ligand 1 (PSGL-1) in the CD34+ cells by polymerase chain reaction (PCR) analysis suggests that this molecule is present in these cells. Under conditions that prevent platelet adhesion, a small but distinct subpopulation of CD34+ cells diffusely expressed the platelet GPIIb/IIIa complex. These cells were visualized by immunochemical studies. Furthermore, synthesis of mRNA for GPIIb and GPIIIa by CD34+ cells was shown using PCR analysis. The semiquantitative PCR results show relatively higher amounts of GPIIb mRNA than of PF4 mRNA in CD34+CD41+ cells in comparison with this ratio in platelets. This finding is a strong indication that the PCR results are not caused by contaminating adhering platelets. MoAbs against GPIa GPIb alpha, GPV, P- selectin, and the alpha-chain of the vitronectin receptor did not react with CD34+ cells. The number of CD34+ cells expressing GPIIb/IIIa present in peripheral blood stem cell (PBSC) transplants was determined and was correlated with platelet recovery after intensive chemotherapy in 27 patients. The number of CD34+CD41+ cells correlated significantly better with the time of platelet recovery after PBSC transplantation (r = .83, P = .04) than did the total number of CD34+ cells (r = .55). Statistical analysis produced a threshold value for rapid platelet recovery of 0.34 x 10(6) CD34+CD41+ cells/kg. This study suggests that if performed in the presence of EDTA the flow cytometric measurement of GPIIb/IIIa on CD34+ cells provides the most accurate indication of the platelet reconstitutive capacity of the PBSC transplant.     

Colonic conduit for esophageal replacement: long-term endoscopic and histopathologic changes in colonic mucosa

BackgroundLong-term follow-up has substantiated the colon as a durable and highly acceptable esophageal substitute. Exposure of colonic conduit to gastric acid may lead to histopathologic changes in the form of chronic inflammation.Materials/MethodsThirty children with esophageal replacement were studied from 2 to 12 years (mean, 5.20 years) postoperatively. All cases underwent upper gastrointestinal tract endoscopy to evaluate the gross appearance of colonic conduit mucosa, and punch biopsies were taken from upper and lower junctions of the conduit. All biopsies were submitted to histopathologic examination.ResultsEndoscopic findings were comparable with normal regarding the gross appearance of colonic mucosa in both upper and lower junctions (25 cases/83.3%). Some abnormalities were seen including cervical anastomosis stricture (2 cases/6.7%), redundancy (3 cases/10%), mucosal ulcer in the lower residual esophagus (1 case/3.3%), and hyperemia (3 cases/10%). Pathologic changes were minimal regarding the change in position of the colon to a thoracic organ during follow-up. Most of the cases were normal (22cases/73.3%). Seven cases (23.4%) showed mild chronic nonspecific inflammation of the colonic mucosa, whereas only 1 case (3.3%) showed mildly active inflammation of colonic mucosa.ConclusionThe use of the colon for esophageal replacement showed that no significant pathologic changes affecting its function as a conduit because its mucosa showed no significant change in response to gastric acid reflux in long-term follow-up and can be further protected by an antireflux procedure.     

Is ASCT With TBI Superior to ASCT Without TBI in Mantle Cell Lymphoma Patients?

BACKGROUND: Impact of total-body irradiation (TBI) in conditioning regimen on outcome for patients with mantle cell lymphoma (MCL) remains unknown. METHODS: Patients with MCL who underwent autologous stem-cell transplantation (ASCT) in our institution were eligible for the present study (n=73). We analyzed the impact of various biologic and clinical parameters, with and without TBI, on patient outcome. RESULTS: All patients presented with chemosensitive disease at transplantation. Median follow-up from ASCT was 37.2 months. One- and three-year overall survival (OS) rates were 90.3% and 74.5%, progression-free survival (PFS) rates were 85% and 59%, respectively. Three-year OS and PFS rates in the non-TBI group versus TBI group were similar: 80% versus 72.5% and 60% versus 57%, respectively. In univariate analysis, the use of TBI did not modify OS or PFS (P=0.93 and P=0.48, respectively). This remains true for patients who underwent ASCT up front. According to multivariate analysis, OS tended to be shorter for patients presenting with high Mantle Cell Lymphoma International Prognostic Index or low hemoglobin level. CONCLUSIONS: Absence of TBI in conditioning regimen modifies neither PFS nor OS. The present retrospective and monocentric analysis shows that transplant patients with MCL remain highly exposed to relapse.     

The effect of Dega acetabuloplasty and Salter innominate osteotomy on acetabular remodeling monitored by the acetabular index in walking DDH patients between 2 and 6 years of age: short- to middle-term follow-up

Introduction

The surgical management of neglected developmental dysplasia of the hip (DDH) in walking children has always been a challenge to orthopedic surgeons. The aim of this study was to evaluate the short- to middle-term clinical and radiographic results of the management of DDH.

Patients and methods

Patients less than 6 years old using two of the most commonly used osteotomies, namely, Salter innominate osteotomy and the Dega acetabuloplasty. Special attention was paid to acetabular remodeling after concentric reduction, which was monitored by the acetabular index, that, in turn, was measured preoperatively, immediately postoperatively, every 6 months, and at the final follow-up examination.

Results

The final overall clinical end results were favorable (excellent or good) in 93 hips (85.3 %). There was a marked improvement of the acetabular coverage during the follow-up period, which proved the good remodeling potential of the acetabulum for this particular age group after concentric reduction was achieved and maintained.

Conclusion

Both osteotomy types were found to be adequate for the management of neglected walking DDH patients under the age of 6 years.